Materials¶

Energy loss true compared to measured¶

Energy residuals upstream (black) and downstream (red)¶

Present¶

Rhys Gardener
Celeste Pidcott
Chris Rogers
John Nugent
Rhys Gardener

Rhys Gardener

• Trying to measure energy loss in the muon beam as they pass through the absorber
  • How much energy absorbed
  • Use trackers to make momentum measurement before and after the absorber
  • Subtract the two to get an energy loss measurement
  • Errors arise from:
    • Momentum resolution of the trackers
    • Systematic from energy loss in materials
      • Effects from materials not significant compared to momentum resolution; 2 MeV from material; take out the systematic by doing an absorber empty run
    • Knowledge of density of material; liquid Hydrogen density, Lithium Hydride density

• Since collaboration meeting
  • Continuing toy analysis doing before the collaboration meeting; taking into account suggestions like off axis beam
  • Particles that lose more energy are reconstructed better; no correlation between transverse momentum and longitudinal momentum reconstruction
  • Start with momentum off centre, 1 % px
  • Normal emittances in x and y
  • Comparing momentum reconstructed in upstream and downstream tracker
• Energy residuals upstream (black) and downstream (red)
  • Rhys to check why plots are not centred on 0

Celeste Pidcott

• Looking at various sources of error; tracker misalignment, hoping for massive monte carlo from tracker group; simulated effect of Helium windows; appears to make a measurable effect; tracking through the fields is not quite working out, large momentum residuals tracking backwards from d/s TRP
  • Use Virtual plane to extract particle position at absorber
  • Used SciFi MonteCarlo hits at the scifi; Rogers suggests using Virtual planes

John Nugent

• Nothing changed since Wednesday; attempting to merge toy remnant field model with CDB geometry, now tracking and looking at the beam distribution
  • Remnant field model done using toy solenoids with small currents to match Holger field map
• Chasing up misalignment; got that installed and working at Glasgow